Proteomic profiling of dog urine after European adder (Vipera berus berus) envenomation by two-dimensional difference gel electrophoresis.

Between April and September every year, many dogs in Finland are bitten by Vipera berus berus, also known as the European adder, the only venomous snake in the area. Exposure to snake bite venom causes local and systemic symptoms and in severe cases can lead to death. Urine samples were collected from four dogs bitten by V. berus berus and treated in the intensive care unit of the Veterinary Teaching Hospital at the University of Helsinki. The inclusion criteria were a strong suspicion of an adder bite no more than two days before admission and clinical signs of an adder bite. Exclusion criteria were defined as ongoing treatment with glucocorticoids or a known history of liver or kidney diseases. Six privately owned, healthy dogs were obtained as controls. Samples were subjected to 2D-DIGE analysis. Image analysis was performed with DeCyder 7.0 2D software, and protein spots demonstrating a minimum 1.5-fold difference in average spot volume ratios between envenomed and control dogs with a Student's t-test p-value of less than 0.05 were picked and identified using LC-MS/MS. In 2D-DIGE analysis, seven proteins were significantly (p < 0.05) over-expressed in the urine of dogs bitten by V. berus berus compared to the control group. From these, five proteins were identified: beta-2-microglobulin (b2MG), alpha-1-antitrypsin (AAT), albumin, fetuin-B and superoxide dismutase (SOD1). Results indicate that envenomation by V. berus berus alter the urinary protein profile in dogs.